What is claimed is the ornamental design for a snow thrower, as shown and described.
FIG. 1 is a front perspective view of a snow thrower showing our new design;
FIG. 2 is a front side view thereof;
FIG. 3 is a rear side view thereof;
FIG. 4 is a left side view thereof;
FIG. 5 is a right side view thereof;
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom plan view thereof.
Any elements shown in dotted and/or dashed lines are provided for illustrative purposes only and form no part of the design claimed. Any surface shading is used solely to show the character or contour of the surfaces represented.